The present invention relates to a method of treating dry cows for mastitis as well as to a composition of matter particularly suited for such treatment. More particularly, the present invention relates to the use of a limited solubility penicillin salt, preferably in a slow release base, for the treatment of cows for mastitis during the dry or non-milking period. In addition, an antibiotic neomycin may be added to the composition to overcome mastitis causing bacteria which are resistant to the action of penicillin.
In the treatment of cows during the dry or non-milking period to overcome bovine mastitis the use of high solubility penicillin salts and complementary antibiotics have heretofore been applied in dosages of high concentration. For example, such a treatment product would contain 1,000,000 units of procaine penicillin G and 1,000 milligrams of dihydrostreptomycin. Such high dosage units have the obvious disadvantage of high cost and, in some cases, the desired residual effects of the procaine penicillin G remain in the udder of a treated cow for only a few days. As a result, it is necessary to repeat dosages at short intervals in order to maintain a sufficiently high residual procaine penicillin G level in the animal being treated. The practice of retreatment in dry cows is impractical and undesirable. It is impractical because the cow is usually put out to pasture during the dry period and, therefore, not easily accessible for treatment and it is undesirable because retreatment breaks the teat seal which forms naturally during the dry period to protect the udder from invasion by bacteria.
It is an object of the present invention to provide a composition of matter which is particularly suited for the treatment of cows for bovine mastitis during their dry period. It is also an object to provide a composition of matter wherein the product has a penicillin salt of limited solubility in a slow release base so that the effectiveness of the penicillin is prolonged over an extended period of time. It is still a further object to incorporate into the composition of matter neomycin and/or other antibiotics to treat other bacteria, such as Escherichia coli, Aerobacter aerogenes, Klebsiella sp., and some strains of Staphylococcus aureus bacteria which are insensitive or resistant to penicillin.